Merge pull request #295 from phase2/feature/storybook-6.4.21

feat(storybook): Upgrade Storybook to 6.4.21.

package.json

@@ -103,14 +103,14 @@
     "@rollup/plugin-json": "^4.1.0",
     "@rollup/plugin-multi-entry": "^4.0.0",
     "@rollup/plugin-replace": "^2.4.2",
-    "@storybook/addon-a11y": "^6.4.20",
-    "@storybook/addon-actions": "^6.4.20",
-    "@storybook/addon-essentials": "^6.4.20",
-    "@storybook/addon-links": "^6.4.20",
+    "@storybook/addon-a11y": "^6.4.21",
+    "@storybook/addon-actions": "^6.4.21",
+    "@storybook/addon-essentials": "^6.4.21",
+    "@storybook/addon-links": "^6.4.21",
     "@storybook/addon-postcss": "^2.0.0",
-    "@storybook/builder-webpack5": "^6.4.20",
-    "@storybook/manager-webpack5": "^6.4.20",
-    "@storybook/web-components": "^6.4.20",
+    "@storybook/builder-webpack5": "^6.4.21",
+    "@storybook/manager-webpack5": "^6.4.21",
+    "@storybook/web-components": "^6.4.21",
     "@tailwindcss/aspect-ratio": "^0.4.0",
     "@tailwindcss/forms": "^0.4.0",
     "@tailwindcss/typography": "^0.5.0",
@@ -153,7 +153,7 @@
     "rollup-plugin-terser": "^7.0.2",
     "rollup-plugin-typescript2": "^0.31.2",
     "rsync": "^0.6.1",
-    "storybook": "^6.4.20",
+    "storybook": "^6.4.21",
     "svgo": "^2.7",
     "tailwindcss": "^3.0.0",
     "ts-lit-plugin": "^1.2.1",